1. Field of the Invention
The present invention relates generally to clamps. More particularly, the present invention relates to a pipe leak repair clamp assembly.
2. Description of the Related Art
Pipe clamps employing interlocking lugs and a tightening nut and bolt and useful for tightening a flexible steel band around a gasket to stop a leak in the pipe are well known devices. Known devices have a relatively high profile and are subject to pulling apart upon tightening the clamp when one end of the steel band pulls away from one of the lugs. It would be desirable to have a lug-type pipe clamp which has a relatively low profile to avoid interference with other pipes or structures in the immediate vicinity. It would also be desirable to provide a clamp design which will not pull apart upon tightening and will accomodate a wide range of pipe sizes.
U.S. Pat. No. 3,680,180, issued Aug. 1, 1972, to Gould et al., describes a low-profile wide-range pipe clamp adapted for encircling a pipe as a leak repair. The clamp assembly includes a flexible metal band having a gasket liner for sealing the defective section of pipe. The tightening pressure on the pipe is provided by screwing a bolt, which brings the side lugs together, resulting in the metal band tightening around the pipe. A gap bridge is provided to prevent the gasket from extruding between the spaced ends of the metal band. Each lug has a slot and a bore in which an end of the metal band is held using a rod.
U.S. Pat. No. 3,700,008, issued Oct. 24, 1972, to Hackman, describes a pipe clamp with an improved gap bridge. The clamp comprises a pipe encircling band with opposing folded ends, a sealing elastomeric gasket liner, tightening lugs, and a gap bridge member.
U.S. Pat. No. 4,413,388, issued Nov. 8, 1983, to Akhtar-Khavari et al. describes a pipe repair clamp having opposed lugs with retaining slots disposed in the base portions of the lugs to hold the folded ends of the flexible band. A steel bridge plate is interposed between the gasket and the band bridging the open space between the bases of the lugs. This prevents deformation of the gasket into the open space and ensures a uniform sealing pressure on the gasket.
U.S. Pat. No. 3,889,324, issued Jun. 17, 1975, to Glover, describes a pipe repair clamp having clamp lugs defining a longitudinal, non-circular cavity in which to receive the band ends looped in a generally similar cross section thereof. A noncircular staking bar is longitudinally positioned within each band loop in force fit engagement in opposition to increasing draw forces tending to urge separation between the band and jaw, the bar operably acting as a rotational interlock to increase gripping tension therebetween.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a pipe leak repair clamp solving the aforementioned problems is desired.
The present invention is a leak repair clamp for sealing a leak in a pipe. The repair clamp includes a flexible, circular metal band lined with a gasket for sealing a leak. The clamp further includes a tightening assembly comprising a pair of open and close lugs and a nut and bolt for tightening the band around a leaking pipe. Each lug includes an open slot leading to an inner recess adapted to firmly engage a folded end of the flexible metal band. The slot is about equal to the thickness of the band and the recess is configured to hold a multiple folded end of the flexible metal band by providing lower and upper walls expanding radially from the grooves which engage the folded end, the recess being of such dimensions as to maintain folded each end in its original shape, thus preventing the metal band from being pulled from the slot upon tightening the clamp.
The open slots divide the lugs into upper and lower or pressure jaws. The lugs have chamfers extending along their respective pressure jaws tapering upward toward the respective pressure jaw open ends. When the open and close lugs are assembled with the nut and bolt, the slot in each lug open toward each other and are coplanar. The lugs are installed with sufficient clearance between the lugs that the chamfer of each lug pressure jaw is substantially perpendicular to a radius of the pipe near the pressure jaw end. This allows for the bolt to extend close to the pipe and thus lowers the profile of the clamp. Also, the chamfered pressure jaw reduces the downward tension on the metal band when tightening, thus reducing the tendency for the end of the band to pull out of the groove upon tightening the clamp. The configuration of the pressure jaw also allows the use of the clamp to repair a large range of pipe sizes. A relatively large bridge plate is provided to allow use of the inventive clamp for such a large range of pipe sizes.
Accordingly, it is a principal object of the invention to provide a pipe clamp for sealing leaks having a low profile.
It is another object of the invention to provide a pipe clamp as above having slotted lugs which have chamfered lower pressure jaws exerting a lower downward tension on metal strips held therein.
It is a further object of the invention to provide a pipe clamp as above, said slots opening into recesses adapted to maintain the folded ends of the metal strips tightly secured therein.
Still another object of the invention is to provide a pipe clamp as above having a configuration for folding the ends of the metal strips so as to remain firmly held within said lugs.
Yet another object of the invention is to provide a pipe clamp as above which fits a large range of pipe diameters.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.